Honing element



July 20, 1965 w. G. cRowE HONING ELEMENT Filed July 2. 1965 INVENTOR. WILLIAM G. CROWE mi MMQMWL ATTORNEYS United States Patent O 3,195,280v HGNING ELEMENT William G. Crowe, Brighton, Mich., assigner to Mid-West Abrasive Company, Owosso, Mich., a corporation of Delaware Filed July 2, 1963, Ser. No. 292,337 Claims. (Cl. 5l-204) This invention relates generally to a honing assembly and refers more particularly to the honing elements for such an assembly.

One object of this invention is to provide honing elements for a honing assemblywhich are capable of being inexpensively manufactured and yet Which are extremely efficient in the performance of its intended function.

Another object is to provide a honing element which is designed to have a maximum cooling effect.

Another object is to provide a honing element so constructed as to provide'a pocket or pockets which serve as a reservoir for coolant.

Another object is to provide a honing element composed of an elongated abrasive stick and a holder for the stick having non-abrasive tabs at the ends of the stick which tabs are narrower than the stick to provide pockets or reservoirs for the cooling medium.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying rawing, wherein:

FIGURE 1 is a side elevational view of a honing head z Vhoning elements.

FIGURE 3 is an end view of the honing element.

FIGURE 4 is a top plan view of the honing element.

FIGURE 5 is a sectional View illustrating the adjusting member of the honing head in engagement With one of the honing elements.

FIGURE 6 illustrates a modified honing element in end elevation.

Referring now more particularly to the drawing and especially to FIGURES 1 5, the honing tool is semidiagrammatically indicated at lil and comprises an elongated tubular head 12 which has a plurality of circumferentially spaced slots I4 elongated in the direction of length of the head. Honing elements 16 of identical construction are respectively disposed in the slots for radially in and out movement.

Each honing element 16 comprises an elongated holder 18 and an elongated bonded abrasive stick .'Zil of uniform rectangular cross-section throughout its length. Actually, the cross-section may not be quite rectangular because the working face Z2 of the abrasive stick will become crowned somewhat in use due to contact with the cylindrical surface of an internal bore being honed.

The holder 18 has an elongated base 24 provided with a flat front face 26. The back surface 23 of the base is inclined as shown in FIGURE 2 for reasons which will become more apparent as the description proceeds. i

The abrasive stick extends lengthwise of the base of the holder and is secured to the front surface 26 thereof by a suitable cement. The width of the stick is the same as the Width of the base and therefore the flat parallel sides 30 of the stick are flush with the flat parallel sides 32 of the base., FIGURE 6 illustrates a moditication ICC which differs only that the thrust or trailing side of the stick has a non-abrasive coating 33 which may be an epoxy resin coating and which is flush with the corresponding side of the base to reduce or prevent slot wear.

The holder also has tabs 34 and 36 which project from the front surface 26 of the base at the ends thereof, which tabs are formed integrally with and of the same material as the base. The tabs extend along the ends of the stick in abutting relation therewith. The cement for permanently securing the stick to the front surface 26 of the base may also be applied to the ends of the stick `and to the tabs where these members contact one another so tha-t there is also an adhesive bond between the tabs and the stick.

The tabs 34 and 36 will be seen in FIGURES 3 and 4 to be narrower than the base yand also narrower than the stick. Thus the tabs will be observed to be centered with respect to the stick. The ilat front surface of the base extends beyond the ends of the stick to the extreme ends of the base on both sides of each tab. The base and tabs are rounded somewhat at the ends to conform more or less with the outline of the slots. The front faces 3S and dil of the tabs are disposed in the plane of or flush with the front working face 22 of the stick. As seen in the drawing, these front faces 38 and 40 provide extensions of the Working face of the stick. There is little, if any, gap between the front working face of the stick and the front surfaces of the tabs because of the substantially abutting relationship therebetween. The front faces of the tabs will wear with the stick and hence will have the same contour as that of the stick which may be slightly rounded or crowned after use.

The holder 18 may be formed of any one of `a number of materials depending to some extent on the character of the abrasive sticks. Metal is preferred, and such metal as magnesium or aluminum or alloys containing these metals are generally suitable for use in connection with most types of abrasive sticks. Actually, it would be possible to fabricate the holder from various resins, preferably thermosetting, such for example as a phenolic resin. In any event a material is selected which possesses the required strength `and has a wear resistance no greater than that of the abrasive stick. Ordinarily, the holder has a wear resistance approximately equal to that of the stick so that the tabs will wear at the same rate as the stick. Accordingly, the surfaces 33 and 4t) of the tabs will remain flush with the outer Working face 22 of the stick, and the surface 38 of the tab 34 may be used .as a gauging surface for determining the diameter of the abrasive head by a gauging device 42.

lt was stated that a metal holder is preferred. Metal has been found to be of a more porous nature than plastic. The greater porosity of the metal holders, especially at the front or outer surfaces of the tabs, acts to entrap coolant and results in a more uniform breakdown or wear when in contact with the workpiece.

The gauging device 42 is indicated generally in FIG- URE l and is not shown in greater detail because it forms no part of the invention. It will be sufficient to point out that the gauging device is applied to the honing tool l0 and has radially adjustable shoes which are contacted by the tab surfaces 38 when the head l2 is moved to its uppermost position relative to the Work. Since the tabs Wear uniformly with the stick, engagement of the surfaces 38 of the several honing elements with the gauging 3 device alfo'rds an'accurate measurement of the effective diameter of the honing assembly.

Guide elements (not shown) of bre or other similar` material are supported on lthe head l?.v between the abrasive elements in order to position the head when the Y tact with the bore. In operation, the honing head recip- .rocates within the bore and at the same time rotates to `abrade the surface of Ithe bore. As the head moves on its upward stroke the surfaces 38 of the upper tabs move Vwithin the gauging device.

y It is preferred to coat the trailing or thrust side of each abrasive stick (FGURE 6) because in use the trailing the temperature within satisfactory limits, but also servesto keep the stonesY clear and flushed of the honing silt, that is the particles of metal, abrasive, bond, or any foreign material Vin the bore. on the working face of the stick and form a glaze over it unless there is suihcient coolant to flush the silt and to prevent the silt from getting hot enough to form a glaze.

The amount of coolant that can be maintained in contactr Awith the honing elements, yand particularly with the working faces of the abrasive sticks, has been found to bei' greatly increased by the pocket construction of the abrasive elements. The pockets collect the coolant and provide a reservoir from which it spreads directlyover those surfaces of the stick and holder which contact the work. The cooling medium also moves directly from the pocket reservoirs along the leading edges of the working faces of the sticks.

Probably the most important pocketis the onek formed by the upper tab 34 adjacent the leading edge of the `abrasive element, which pocket is designated 52. By the leading edge is meant that edge of the stone which faces toward the direction of rotation of the honing head. Arrow 53 indicates the direction of rotation. provides a reservoir from which coolant can move directly down along the le-ading edge of the stick. This side oredge of the stick is exposed, in both the FEGURES l land FIGURE 6 embodiments, and accordingly the coolant moves readily over the working face. The pocket at the opposite side of the upper tab, that is at the Vtrailing or thrust side, also collects coolant which is distributed down the trailing edge of the abrasive element and likewise facilitates the-flushing of silt from the abrasive elementsv and from the regions adjacent thereto. The pockets formed on either side of the lower tab also collect coolant during the down stroke, which is distributed along the leading and trailing edges particularly during the up stroke.

Heretofore, the coolant introduced at the top of the bore either ran directly down the walls of the bore in no special -relationshiprto the honing elements, or was thrown olf by centrifugal force and the full benefit of the coolant was not realized. The pocket construction of the honing elements provides, in effect, restrictions which vcollect the coolant in reservoirs located in close proximity This honing silt may collect Pocket 52 to the critical trailing and yleading edges of the abrasive stick and from whichthe coolant can be discharged along those edges for maximum cooling and flushing efficiency.

Sometimes in the pastit has been necessary to force the honing elements outward under considerable pressure in order to break down the glaze over the abrasive so that fresh abrasive could be presented to the work. lHoning eieinents constructed according to the resent invention provide a suiiicient increase in the amount of coolant over the working faces of the honing elements that the silt is fin-shed away before a glaze can form.

What I claim as my invention is: ll. A honing element for a honing tool, comprising a substantially rectangular bonded abrasive stick, and an elongated holder therefor having an elongated base of substantially the same width but of greater length than said abrasive stick, the front of said elongated base being provided at opposite ends thereof with forwardly projecting integral tabs disposed at opposite ends of said abrasive stick and having a width less than said base and less than said abrasive sticksaid base being provided between and upon opposite sides of said tabs'with a at front surface whereby thelportions of the VflatV surface upon opposite sides of saidtabs in'cooperation with said tabs and the opposite ends of saidVV abrasive stick provide pockets for the reception of a cooling medium, the rear surface of .said -abrasive stick being `secured to the at front surface of said elongated base, the front surface of said abrasive stick being` substantially flush'with the forward ends of said tabs. n

2. The honing element defined in claim 1, wherein the tabs Yabut and are secured to said abrasive stick.

3. The honing element defined in claim 1, wherein the base and the Vtabs have rounded ends hush with each other.

4. The honing element defined in claim ll, wherein the holder including the base and the tabs are formed hom metal, and said holder has .la wear resistance approximately equal to that of said `abrasive stick, whereby said tabs are adapted to wear at the same rate as said abrasive stick.' I Y 5. The honing element defined in1claim 1, wherein at least one side Vedge of said abrasive stick has a nonabrasive coating substantially flush with the corresponding edge of said baseto reduce wear. f

6. The honing element defined in claim 1, wherein at leastrone side edge of said labrasive stick is uncovered and is exposed. p v

7. 'The honing element defined-in claim 1, wherein the holder including the base and the `tabs are formed from resinous material. Y Y Y 8.V A honing element for a honing tool, comprising a Vsubstantially rectangular bonded abrasive stick, and an elongated holder therefor having an elongated baseV eX- tending lengthwise of and'being of greater length than said abrasive stick, the front of ksaid Velongated .base being provided at oneY end thereof with a forwardly projecting tab disposed at one end of said abrasive stick and having a width less than said base and less than said abrasive stick said basebeing provided with a at front surface Vto which the rear surface of said abrasive stick is secured, Vsaidlat front surface ,having a portionl extending upon flat front surface in cooperation with said `tab and said one end of said abrasive stick providing a second pocket for the reception of a cooling medium.

10. A honing element for a honing tool, comprising a medium, the front surface of said abrasive stick being substantially rectangular bonded abrasive stick, and an SllbStaIlially llSh With the fOrWaId end 0f Said tab. elongated holdei` therefor having an elongated base eX- Refeens Cite by the Examiner tending lengthwise of and being of greater length than UNHTED S ATES PATPNTG said abrasive stick, the rear of said stick being secured 5 l T H o t to the front of said base, said base having at one end 21311755 2/43 Jack son 51-204 thereof a forwardly projecting tab disposed at one end ot --515 l u y 1` g n o sald abraslve stick, said tab having a Wldth less than 3,037,333 6/62 Stelmachowsk n 51-346 said base and less than said abrasive stick to provide a 10 pocket which is open at the side of said honing element LESTER M. SWINGLE, Primary Examiner. and at the front thereof for the reception of a cooling j. SPENCER OVERHQLSER, Exam-erI 

10. A HONING ELEMENT FOR A HONING TOOL, COMPRISING A SUBSTANTIALLY RECTANGULAR BONDED ABRASIVE STICK, AND AN ELONGATED HOLDER THEREFOR HAVING AN ELONGATED BASE EXTENDING LENGTHWISE OF AND BEING OF GREATER LENGTH THAN SAID ABRASIVE STICK, THE REAR OF SAID STICK BEING SECURED TO THE FRONT OF SAID BASE, SAID BASE HAVING AT ONE END THEREOF A FORWARDLY PROJECTING TAB DISPOSED AT ONE END OF SAID ABRASIVE STICK, SAID TAB HAVING A WIDTH LESS THAN SAID BASE AND LESS THAN SAID ABRASIVE STICK TO PROVIDE A POCKET WHICH IS OPEN AT THE SIDE OF SAID HONING ELEMENT AND AT THE FRONT THEREOF FOR THE RECEPTION OF A COOLING MEDIUM, THE FRONT SURFACE OF SAID ABRASIVE STICK BEING SUBSTANTIALLY FLUSH WITH THE FORWARD END OF SAID TAB. 